Final answer:
The reader would learn Tommy's initial thoughts and feelings upon seeing Robin and hearing the knock. Tommy's narrative could reveal his own perceptions and romanticized memories of their first encounter.
Step-by-step explanation:
If the story narrated by Robin were told from Tommy's perspective, the reader would likely gain insight into what Tommy thought when he saw Robin and what Tommy felt on hearing the knock at the door.
Since the current narration mentions Tommy insisting on details like Robin's blushing and mistaken attire, it can be inferred that his version would include his initial impressions and feelings about Robin which could be quite different than Robin's account.
Furthermore, if Tommy was the one narrating, we might understand his own perceptions and potentially why he remembered the events differently, such as Robin wearing a yellow sundress instead of jeans, which reflects his personal biases or romanticized recollections.